core/job: emit job start message if we're only waiting for unit state

Currently, start/stop messages for device units are not used, since
job_perform_on_unit() does nothing and we simply wait for unit status
change. I think we still want some nice log messages explaining what
the start jobs for devices are doing, so let's fix this.

diff --git a/src/core/job.c b/src/core/job.c
index e7d1f65dbccd8481b05562f479b732f7c00efcd3..e78c2a70db6015c15fc0f4823cfab4c96fa40464 100644 (file)
--- a/src/core/job.c
+++ b/src/core/job.c
@@ -833,13 +833,12 @@ static int job_perform_on_unit(Job **j) {
         Manager *m;
         JobType t;
         Unit *u;
+        bool wait_only;
         int r;
 
-        /* While we execute this operation the job might go away (for
-         * example: because it finishes immediately or is replaced by
-         * a new, conflicting job.) To make sure we don't access a
-         * freed job later on we store the id here, so that we can
-         * verify the job is still valid. */
+        /* While we execute this operation the job might go away (for example: because it finishes immediately
+         * or is replaced by a new, conflicting job). To make sure we don't access a freed job later on we
+         * store the id here, so that we can verify the job is still valid. */
 
         assert(j);
         assert(*j);
@@ -853,6 +852,7 @@ static int job_perform_on_unit(Job **j) {
         switch (t) {
                 case JOB_START:
                         r = unit_start(u, a);
+                        wait_only = r == -EBADR; /* If the unit type does not support starting, then simply wait. */
                         break;
 
                 case JOB_RESTART:
@@ -860,24 +860,28 @@ static int job_perform_on_unit(Job **j) {
                         _fallthrough_;
                 case JOB_STOP:
                         r = unit_stop(u);
+                        wait_only = r == -EBADR; /* If the unit type does not support stopping, then simply wait. */
                         break;
 
                 case JOB_RELOAD:
                         r = unit_reload(u);
+                        wait_only = false; /* A clear error is generated if reload is not supported. */
                         break;
 
                 default:
                         assert_not_reached();
         }
 
-        /* Log if the job still exists and the start/stop/reload function actually did something. Note that this means
-         * for units for which there's no 'activating' phase (i.e. because we transition directly from 'inactive' to
-         * 'active') we'll possibly skip the "Starting..." message. */
+        /* Log if the job still exists and the start/stop/reload function actually did something or we're
+         * only waiting for unit status change (common for device units). The latter ensures that job start
+         * messages for device units are correctly shown. Note that if the job disappears too quickly, e.g.
+         * for units for which there's no 'activating' phase (i.e. because we transition directly from
+         * 'inactive' to 'active'), we'll possibly skip the "Starting..." message. */
         *j = manager_get_job(m, id);
-        if (*j && r > 0)
+        if (*j && (r > 0 || wait_only))
                 job_emit_start_message(u, id, t);
 
-        return r;
+        return wait_only ? 0 : r;
 }
 
 int job_run_and_invalidate(Job *j) {
@@ -919,13 +923,6 @@ int job_run_and_invalidate(Job *j) {
                 case JOB_START:
                 case JOB_STOP:
                 case JOB_RESTART:
-                        r = job_perform_on_unit(&j);
-
-                        /* If the unit type does not support starting/stopping, then simply wait. */
-                        if (r == -EBADR)
-                                r = 0;
-                        break;
-
                 case JOB_RELOAD:
                         r = job_perform_on_unit(&j);
                         break;